1. Field of Invention
This invention relates to a medical device, specifically a device to dilate and retract the walls of a body cavity.
2. Description of Prior Art
Traditional devices for dilating body cavities include medical or surgical instruments known variously as specula, dilators, or retractors. The term speculum or dilator is usually used to designate a device, which enlarges, dilates, allows easier access to, or better visualization of an existing body cavity, such as a vagina, ear, nose, or rectum. The term retractor, on the other hand, is usually reserved to designate a device used during a surgical procedure where an incision is made into the body and a temporary opening into the body is made. The walls of the incised portion of the body are then held apart by means of retractors so that the surgeon can operate inside this temporary opening. For the purposes of this patent application, the term speculum will be used to refer to a device that can perform not only the functions of a speculum or dilator, but that also of a retractor.
The specula, that have been patented in the past, can be placed in one of the following categories:
1. A single-bladed speculum that either has to be
(a) held in place by an assistant, PA1 (b) attached to the body in some manner (U.S. Pat. No. 3,853,120 to Batista, U.S. Pat. No. 3,709,215 to Richmond), or PA1 (c) held in place by gravity. PA1 (a) parallel to each other (U.S. Pat. No. 350,721 to Cooper, U.S. Pat. No. 351,548 to Watson, U.S. Pat. No. 361,087 to Schenck, U.S. Pat. No. 761,821 to Clark et al, U.S. Pat. No. 1,614,065 to Guttmann, U.S. Pat. No. 2,374,863 to Guttmann, U.S. Pat. No. 579,625 to Willbrandt, U.S. Pat. No. 1,194,319 to Pretts, U.S. Pat. No. 605,547 to Holland, U.S. Pat. No. 1,014,799 to Arthur, U.S. Pat. No. 3,030,947 to Engelbert, U.S. Pat. No. 3,176,682 to Wexler, U.S. Pat. No. 3,509,873 to Karlin et al), or PA1 (b) radially to each other (U.S. Pat. No. 639,444 to Scheerer, U.S. Pat. No. 658,669 to Morrow, U.S. Pat. No. 786,457 to McGinnis). PA1 (a) parallel to each other (U.S. Pat. No. 151,228 to Knaffl, U.S. Pat. No. 977,489 to Von Unruh, U.S. Pat. No. 1,018,868 to Breneman, U.S. Pat. No. 1,500,227 to Breneman, U.S. Pat. No. 2,083,573 to Morgan, U.S. Pat. No. 5,183,032 to Villalta et al, U.S. Pat. No. 5,081,983 to Villalta et al), or PA1 (b) radially to each other (U.S. Pat. No. 55,511 to Leutz, U.S. Pat. No. 5,509,893 to Pracas).
2. The traditional "duck-billed" speculum having two opposed concavoconvex blades (U.S. Pat. No. 3,716,047 to Moore et al, among many others).
Frequently the handle and lower blade are integral parts of the same piece of material. The upper blade is pivotally attached to a sliding member that runs vertically and is attached to the proximal end (that closest to the operator) of the lower blade/handle complex. The upper speculum blade can be adjusted vertically to enlarge the proximal opening of the speculum. Then, after this is fixed in place, the speculum can be opened or diverged. The proximal end of the upper blade that is pivotally fixed to the lower blade/handle complex then remains the same vertical distance from the proximal end of the lower blade whereas the distal portion of the upper blade (that furthest from the operator) moves vertically from the distal portion of the lower blade.
At full divergence, the longitudinal axes of the upper and lower blades of the "duck-billed" speculum can be thought to meet at a point outside the body cavity, and therefore can be likened to the radii of a circle. Thus, the movement of the upper blade with respect to the lower blade can be said to be radial.
Parallel movement of the blades with respect to each other, of certain other specula, can be said to occur when the longitudinal axes of the upper and lower blades are parallel during divergence and convergence. Thus, the distance between the blades at the proximal and distal ends is always the same.
3. A three-bladed speculum in which, during divergence or convergence, the blades either move:
4. A four-bladed speculum in which, during divergence and convergence, the blades either move:
5. A five-or-more-bladed speculum (U.S. Pat. No. 5,505,690 to Patton et al).
The disadvantages of the specula that have been previously patented can be summarized as follows:
1. Conventional specula are manufactured of surgical steel that need to be sterilized after each use to prevent cross contamination between patients (U.S. Pat. No. 350,721 to Cooper, U.S. Pat. No. 351,548 to Watson, U.S. Pat. No. 361,087 to Schenck, U.S. Pat. No. 761,821 to Clark et al, U.S. Pat. No. 1,614,065 to Guttmann, U.S. Pat. No. 2,374,863 to Guttmann, U.S. Pat. No. 579,625 to Willbrandt, U.S. Pat. No. 1,194,319 to Pretts, U.S. Pat. No. 605,547 to Holland, U.S. Pat. No. 1,014,799 to Arthur, U.S. Pat. No. 3,030,947 to Engelbert, U.S. Pat. No. 3,176,682 to Wexler, U.S. Pat. No. 3,509,873 to Karlin et al, U.S. Pat. No. 639,444 to Scheerer, U.S. Pat. No. 658,669 to Morrow, U.S. Pat. No. 786,457 to McGinnis, U.S. Pat. No. 151,228 to Knaffl, U.S. Pat. No. 977,489 to Von Unruh, U.S. Pat. No. 1,018,868 to Breneman, U.S. Pat. No. 1,500,227 to Breneman, U.S. Pat. No. 2,083,573 to Morgan, U.S. Pat. No. 5,183,032 to Villalta et al, U.S. Pat. No. 5,081,983 to Villalta et al, U.S. Pat. No. 55,511 to Leutz).
Such sterilization is time consuming and costly necessitating equipment, labor, and quality control to ensure adequate cleaning and sterilization.
Furthermore, steel devices take on the temperature of the ambient air, which in most circumstances, is 20 + degrees Fahrenheit colder than a patient's body temperature.
Typical examinations of body cavities in a conscious patient ordinarily are anxiety provoking. Accordingly, the added shock of a cold surgical instrument applied to the tissue of the patient heightens the anxiousness of the patient. Furthermore, anxious patients may have more tightly tensed muscles that impede the dilation of the body cavity being examined. Thus, they are that much more uncomfortable. The physical examination of the body cavity is thus hampered and slowed.
2. The actual divergence and convergence of the blades of many specula are accomplished by applying forces that aren't applied directly perpendicularly to the walls of the body cavity being dilated (U.S. Pat. No. 350,721 to Cooper, U.S. Pat. No. 351,548 to Watson, U.S. Pat. No. 361,087 to Schenck, U.S. Pat. No. 761,821 to Clark et al, U.S. Pat. No. 1,614,065 to Guttmann, U.S. Pat. No. 2,374,863 to Guttmann, U.S. Pat. No. 1,014,799 to Arthur, U.S. Pat. No. 3,030,947 to Engelbert, U.S. Pat. No. 658,669 to Morrow, U.S. Pat. No. 2,083,573 to Morgan, U.S. Pat. No. 5,509,893 to Pracas).
Applying such indirect forces means that a greater total force is needed, thus making it harder to operate such specula and increasing operator fatigue.
3. The actual mechanism that holds the blades in divergence in many specula (and that needs to be undone for convergence) involves turning a screw or wingnut a number of revolutions (U.S. Pat. No. 350,721 to Cooper, U.S. Pat. No. 351,548 to Watson, U.S. Pat. No. 361,087 to Schenck, U.S. Pat. No. 761,821 to Clark et al, U.S. Pat. No. 1,614,065 to Guttmann, U.S. Pat. No. 2,374,863 to Guttmann, U.S. Pat. No. 1,194,319 to Pretts, U.S. Pat. No. 605,547 to Holland, U.S. Pat. No. 1,014,799 to Arthur, U.S. Pat. No. 3,030,947 to Engelbert, U.S. Pat. No. 3,509,873 to Karlin et al, U.S. Pat. No. 639,444 to Scheerer, U.S. Pat. No. 658,669 to Morrow, U.S. Pat. No. 151,228 to Knaffl, U.S. Pat. No. 977,489 to Von Unruh, U.S. Pat. No. 5,183,032 to Villalta et al, U.S. Pat. No. 5,081,983 to Villalta et al, U.S. Pat. No. 55,511 to Leutz).
Such a mechanism takes an undue amount of time to both set up and take down.
4. Many specula, as designed, have blades that substantially obstruct the view of the walls of the body cavity being dilated or totally encircle the body cavity being dilated (U.S. Pat. No. 350,721 to Cooper, U.S. Pat. No. 351,548 to Watson, U.S. Pat. No. 361,087 to Schenck, U.S. Pat. No. 761,821 to Clark et al, U.S. Pat. No. 1,614,065 to Guttmann, U.S. Pat. No. 2,374,863 to Guttmann, U.S. Pat. No. 605,547 to Holland, U.S. Pat. No. 1,014,799 to Arthur, U.S. Pat. No. 3,030,947 to Engelbert, U.S. Pat. No. 3,176,682 to Wexler, U.S. Pat. No. 639,444 to Scheerer, U.S. Pat. No. 658,669 to Morrow, U.S. Pat. No. 786,457 to McGinnis, U.S. Pat. No. 151,228 to Knaffl, U.S. Pat. No. 977,489 to Von Unruh, U.S. Pat. No. 2,083,573 to Morgan, U.S. Pat. No. 5,183,032 to Villalta et al, U.S. Pat. No. 5,081,983 to Villalta et al, U.S. Pat. No. 55,511 to Leutz, U.S. Pat. No. 5,509,893 to Pracas).
Such a design does not allow operations to be done on the walls of the body cavity being dilated (such as repair of episiotomies or vaginal tears just after delivery) or outside the body cavity (such as repairs of the perineum or rectum after delivery). Some of the devices could perhaps be rotated to allow for this. However, this might render the speculum non-self-retaining and thus require an assistant to hold it in place.
5. Most specula in the prior art, do not have a mechanism to channel light directly into the interior of the cavity they create (U.S. Pat. No. 350,721 to Cooper, U.S. Pat. No. 351,548 to Watson, U.S. Pat. No. 361,087 to Schenck, U.S. Pat. No. 761,821 to Clark et al, U.S. Pat. No. 1,614,065 to Guttmann, U.S. Pat. No. 2,374,863 to Guttmann, U.S. Pat. No. 579,625 to Willbrandt, U.S. Pat. No. 1,194,319 to Prefts, U.S. Pat. No. 605,547 to Holland, U.S. Pat. No. 1,014,799 to Arthur, U.S. Pat. No. 3,030,947 to Engelbert, U.S. Pat. No. 3,176,682 to Wexler, U.S. Pat. No. 3,509,873 to Karlin et al, U.S. Pat. No. 639,444 to Scheerer, U.S. Pat. No. 658,669 to Morrow, U.S. Pat. No. 786,457 to McGinnis, U.S. Pat. No. 151,228 to Knaffl, U.S. Pat. No. 977,489 to Von Unruh, U.S. Pat. No. 1,018,868 to Breneman, U.S. Pat. No. 1,500,227 to Breneman, U.S. Pat. No. 2,083,573 to Morgan, U.S. Pat. No. 5,183,032 to Villalta et al, U.S. Pat. No. 5,081,983 to Villalta et al, U.S. Pat. No. 55,511 to Leutz, U.S. Pat. No. 5,509,893 to Pracas, U.S. Pat. No. 5,505,690 to Patton et al).
Most operators of specula, and others knowledgeable in the art, realize that having a speculum with a mechanism to channel light directly into the interior of a body cavity provides excellent illumination and visualization of that body cavity. Specula, that have no such mechanism, require a light coming from outside the body cavity. This light, besides not being as bright as that light from the above mechanism, can be blocked by the operator, his or her assistant, or another instrument, and usually does not illuminate a part of the vaginal wall since it is coming at an angle from outside the vagina. Excellent illumination is critical to making accurate diagnoses and for operating in the body cavity itself.
6. Many of the more-than-two-bladed specula do not allow the vertical opening of the blades of the speculum to be made independently from the horizontal (U.S. Pat. No. 350,721 to Cooper, U.S. Pat. No. 361,087 to Schenck, U.S. Pat. No. 761,821 to Clark et al, U.S. Pat. No. 1,614,065 to Guttmann, U.S. Pat. No. 2,374,863 to Guttmann, U.S. Pat. No. 579,625 to Willbrandt, U.S. Pat. No. 1,014,799 to Arthur, U.S. Pat. No. 3,030,947 to Engelbert, U.S. Pat. No. 639,444 to Scheerer, U.S. Pat. No. 786,457 to McGinnis, U.S. Pat. No. 977,489 to Von Unruh, U.S. Pat. No. 1,018,868 to Breneman, U.S. Pat. No. 1,500,227 to Breneman, U.S. Pat. No. 2,083,573 to Morgan, U.S. Pat. No. 5,183,032 to Villalta et al, U.S. Pat. No. 5,081,983 to Villalta et al, U.S. Pat. No. 55,511 to Leutz, U.S. Pat. No. 5,509,893 to Pracas, U.S. Pat. No. 5,505,690 to Patton et al).
This mechanism of divergence and convergence does not allow putting differential tension on the walls of the vagina so that the vaginal wall between some blades is taut and between other blades is relaxed. It also does not allow a way for the speculum to be adapted to the anatomic variability that exists among patients.
7. All of the specula, in which the blades move radially, have a fixed opening to the specula (U.S. Pat. No. 639,444 to Scheerer, U.S. Pat. No. 658,669 to Morrow, U.S. Pat. No. 786,457 to McGinnis, U.S. Pat. No. 55,511 to Leutz, U.S. Pat. No. 5,509,893 to Pracas).
This fixed opening restricts access to the opening of the body cavity and lessens visibility to the area to be examined, treated, or on which the surgery needs to be done.
8. Some older devices were designed to be made out of wire (U.S. Pat. No. 658,669 to Morrow, U.S. Pat. No. 151,228 to Knaffl).
The wire specula cannot adequately hold back the walls of whatever body cavity is being dilated.
9. Some specula are not self-retaining (U.S. Pat. No. 1,018,868 to Breneman, U.S. Pat. No. 1,500,227 to Breneman, U.S. Pat. No. 5,183,032 to Villalta et al, U.S. Pat. No. 5,081,983 to Villalta et al).
Non-self-retaining specula require an additional operator to hold such an instrument in place.
In particular, regarding postpartum vaginal examinations, no commercially successful speculum is available that adequately assists in the examination and repair of the cervix or vagina.
What practitioners of the art commonly do now, is to have an assistant hold a wide, single-bladed speculum up against the upper vaginal wall to get that tissue retracted as well as to separate the lateral (side) vaginal walls by draping them over the edges of the single-bladed speculum in this area. Then the practitioner uses his or her nondominant hand to depress the lower vaginal wall to try to get a visual inspection of the vagina and cervix. A weighted vaginal speculum cannot be used since it would hinder examination of the lower vaginal wall for tears and in the repair of the same.
To repair an episiotomy or vaginal tear, the operator needs to continue depressing the effected vaginal wall with their nondominant hand, putting the index finger on one side of the apex of the defect and the third digit on the opposite side. Then using the dominant hand with a suture on a needle holder, they go to the apex of the defect and, going through the vaginal tissue, anchor the first stitch. Then they have to stop depressing the vaginal wall, remove their nondominant hand, and tie the first knot in the suture. Their nondominant hand then again depresses the effected vaginal wall, with the second and third fingers placed on opposite sides of the vaginal defect. The dominant hand then continues suturing the defect until the perineum is reached.
Sometimes even though one uses an anterior blade to retract the upper vaginal wall and the nondominant hand or even a weighted speculum for the lower vaginal wall (after any defects are sutured), one still cannot visualize the cervix because of the redundancy of the postpartum vaginal tissue. Therefore, many times the cervix needs to be inspected by feel. If a defect is felt that needs to be fixed, two ring forceps are placed on either side of the cervical tear. The ring forceps are then pulled toward the operator with the nondominant hand until the cervical tear is visible and then it is sutured.
One can see that this process is very laborious, leading to operator and patient fatigue. It is also quite time consuming, expending valuable operator, support personnel, and delivery room time. It is also prone to incorrect or missed diagnoses and thus incorrect treatment. Taking a long time to diagnose and suture a defect in the cervix or vagina that is bleeding or diagnose and remove a retained piece of placenta, can lead to excessive bleeding. This could cause the patient to be in shock or be severely anemic, either one of which could require a blood transfusion.